Tool-holder.



WILBUR F. TRACY, OF WARREN, MASSACHUSETTS.

TOOL-HOLDER.

Specification of Letters Patent.

- Patented Feb. 18, 1908.

Application filed June 15' 1905. Serial No. 265.430.

To all whom it may concern:

Be it known that I, WVILBUR F. TRACY, a citizen of the United States, residing at Warren, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in a Tool-Holder, of which the following is a specification, accompanied by drawings forming a part of the same, in which Figure 1 is a side elevation of a tool holder embodying my invention. Fig. 2 is a plan view, and Fig. 8 is a central vertical sectional view.

Similar reference letters and figures refer to similar parts in the different views.

My improved tool holder consists of a stem 1 adapted to be held in the tool post of a lathe or similar metal working machine, and having at one end a head 2, provided with an upturned lug 3 to receive a tightening screw 4 and having beneath the lug 3 a mortise 5 to receive a cutting tool 6. The mortise 5 is open at one end to receive the cutting tool which abuts at the opposite end of the mortise against a vertical wall. 7.

The tool holder has an opening 8 in its upper surface immediately behind the lug 8 to expose the inner end of the cutting tool. The thickness of the head 2 exceeds the thickness of the stem 1 forming shoulders 9, 9, and this enlargement of the head over the stem of the holder provides suitable side walls 10, 10, upon each side of the mortise 5, and allows a cutting tool to be used having greater width and rigidity than would be possible in a holder of no greater thickness than the stem 1.

The lateral enlargement of the head extends from the end a short distance beyond the end of the mortise 5, and. the mortise 5 consists of a longitudinal groove formed in the upper edge of the stem. The groove or mortise 5 is partially covered by the lug 3 which connects the side walls of the groove and extends across the groove. The opening 8 at the rear end of the groove allows the groove to be cleared of chips and dirt. By placing the groove at the upper edge of the stem. nearly the entire vertical thickness of the stem is brought beneath the tool, atlording greater strength to the downward pressure upon the tool without unduly increasing the weight of the holder. The upward pressure of the rear end of the holder is received by the tightening screw 4 and this is firmly held in a lug 3 supported by the side walls of the groove which are laterally thickened to furnish the requisite strength and rigidity. By the construction shown I am able to reduce the weight of the holder, at the same time securing strength and rigidity to resist the strains exerted against the cutting tool and prevent jarring or chattering of the tool.

What I claim as my invention and desire to secure by Letters Patent is A tool holder consisting of a stem adapted to be held in a tool post, and provided with a groove in the center of its upper edge extending rearwardly a short distance from its forward end and having an end wall to receive the contact of the tool held therein, said groove being open at its rear end and having the side walls of the groove reinforced by a lateral increase in the thickness of the stem, a lug uniting said side walls and eX- tending over the forward end of said groove, and a tightening screw held in said lug.

WILBUR Fw TRACY.

Vitnesses RUFUS B. FOWLER, PENE OPE OOMBERBACH. 

